Wire Connections Research Articles

Design method of transverse gradient coils based on nonuniform rational B-spline (NURBS) curves.

To propose a hybrid transverse gradient coil design method that leverages current density-based methods and nonuniform rational B-spline (NURBS) curves to optimize the performance and manufacturability of gradient coils. Our method begins by generating an initial wire configuration using a density-based method. Then, we fit NURBS curves to the configuration, and adjust the control parameters of these curves to meet performance requirements. To ensure adequate spacing and even distribution of wires, an objective function utilizing the sigmoid function to modulate the distances between adjacent wires is constructed. Critical factors including gradient efficacy, linearity, eddy current, and torque, are incorporated as constraints. The piecewise nature of the curves provides the flexibility to independently control specific segments without impacting others. We validated our method by designing three shielded transverse gradient coils: a whole-body coil, an ultra-short whole-body coil, and an ultra-short asymmetric head coil. The primary design objectives were to improve linearity and maintain gradient efficiency. All optimized coils demonstrated significant linearity across large diameters of spherical volumes (DSVs), while gradient efficiency, eddy currents, and torque were well-balanced. The objective function effectively managed the wire concentrations required for high linearity, ensuring even wire arrangement and adequate spacing. We leveraged the flexibility of the curves to individually tailor wire paths for specific objectives, such as preventing interference between coils and passive shimming and accommodating wire connections and cooling circuits. This method provides a versatile and effective approach for designing high-performance and manufacturable gradient coils.

Dissimilar Resistance Welding of NiTi Microwires for High-Performance SMA Bundle Actuators

Shape memory alloys (SMAs) are becoming a more important factor in actuation technology. Due to their unique features, they have the potential to save weight and installation space as well as reduce energy consumption. The system integration of the generally small-diameter NiTi wires is an important cornerstone for the emerging technology. Crimping, a common method for the mechanical and electrical connection of SMA wires, has several drawbacks when it comes to miniaturization and high-force outputs. For high-force applications, for example, multiple SMA wires in parallel are needed to keep actuation frequencies high while scaling up the actuation force. To meet these challenges, the proposed study deals with the development of a resistance-welding process for manufacturing NiTi wire bundles. The wires are welded to a sheet metal substrate, resulting in promising functional properties and high joint strengths. The welding process benefits from low costs, easy-to-control parameters and good automation potential. A method for evaluating the resistance-welding process parameters is presented. With these parameters in place, a manufacturing process for bundled wire actuators is discussed and implemented. The welded joints are examined by peel tests, microscopy and fatigue experiments. The performance of the manufactured bundle actuators is demonstrated by comparison to a single wire with the same accumulated cross-sectional area.

Bipolar electrochemical growth of conductive microwires for cancer spheroid integration: a step forward in conductive biological circuitry

The field of bioelectronics is developing exponentially. There is now a drive to interface electronics with biology for the development of new technologies to improve our understanding of electrical forces in biology. This builds on our recently published work in which we show wireless electrochemistry could be used to grow bioelectronic functional circuitry in 2D cell layers. To date our ability to merge electronics with in situ with biology is 3D limited. In this study, we aimed to further develop the wireless electrochemical approach for the self-assembly of microwires in situ with custom-designed and fabricated 3D cancer spheroids. Unlike traditional electrochemical methods that rely on direct electrical connections to induce currents, our technique utilises bipolar electrodes that operate independently of physical wired connections. These electrodes enable redox reactions through the application of an external electric field. Specifically, feeder electrodes connected to a power supply generate an electric field, while the bipolar electrodes, not physically connected to the feeder electrodes, facilitate the reduction of silver ions from the solution. This process occurs upon applying a voltage across the feeder electrodes, resulting in the formation of self-assembled microwires between the cancer spheroids.Thereby, creating interlinked bioelectronic circuitry with cancer spheroids. We demonstrate that a direct current was needed to stimulate the growth of conductive microwires in the presence of cell spheroids. Microwire growth was successful when using 50 V (0.5 kV/cm) of DC applied to a single spheroid of approximately 800 µm in diameter but could not be achieved with alternating currents. This represents the first proof of the concept of using wireless electrochemistry to grow conductive structures with 3D mammalian cell spheroids.

Wireless driven and self-sensing flexible gripper based on piezoelectric elastomer/high-entropy alloy magnetoelectric composite

The mechanical gripper shows significant importance as an alternative to manual work, but presents certain limitations in its gas or electric power with complex wire connection, presents limited available area and loud working noise, and lacks sensing function for feedback to the environment. In the present work, a novel magnetically driven and self-sensing flexible gripper was prepared based on piezoelectric elastomer and high-entropy alloy composite. The high-entropy alloy is prepared as FeCoNi(AlGa)0.5 to realize high permeability, while the piezoelectric elastomer is synthesized with superior elasticity and low modulus. The incorporation of FeCoNi(AlGa)0.5 into the piezoelectric elastomer exhibits high flexibility, magnetostriction performances and piezoelectric responses, reaching maximum strain of 1534.5 %, maximum magnetostrictive coefficient of 320 ppm and maximum piezoelectric response of 0.28 V/N. Meanwhile, the flexible gripper achieves synchronous wireless driven gripping function with a maximum lifting ratio to dead load over 41.38, and self-sensing function of target physical size with accuracy over 95 %. The flexible gripper shows maximum work power as low as 5 W. Thus, the magnetically driven and self-sensing flexible gripper shows great potential in intelligent industrial equipment.

Developing and Testing a Portable Soil Nutrient Detector in Irrigated and Rainfed Paddy Soils from Java, Indonesia

Data on the soil nutrient content are required to calculate fertilizer rate recommendations. The soil laboratory determines these soil properties, yet the measurement is time-consuming and costly. Meanwhile, portable devices to assess the soil nutrient content in real-time are limited. However, a proprietary and low-cost NPK sensor is available and commonly used in IoT for agriculture. This study aimed to assemble and test a portable, NPK sensor-based device in irrigated and rainfed paddy soils from Java, Indonesia. The device development followed a prototyping approach. The device building included market surveys and opted for an inexpensive, light, and compact soil sensor, power storage, monitor, and wire connectors. Arduino programming language was used to write scripts for data display and sub-device communication. The result is a real-time, portable soil nutrient detector that measures the soil temperature, moisture, pH, electrical conductivity, and N, P, and K contents. Field tests show that the device is sensitive to soil properties and location. The portable soil nutrient detector may be an alternative tool for the real-time measurement of soil nutrients in paddy fields in Indonesia.

Multiple-Split Transmitting Coils for Stable Output Power in Wireless Power Transfer System with Variable Airgaps

In this paper, a tunable multi-split transmitting (TX) coil for a wireless power transfer (WPT) system that accommodates a wide range of distances between the TX and receiving (RX) coils is proposed. This method enables the WPT system to maintain a stable and consistent output power supply to the load, regardless of variations in coupling coefficients caused by changes in the distance between the TX and RX coils. The tunable multi-split TX coil can operate in various modes depending on how the wire connections between each TX coil are configured. This approach adjusts the inductance value of the TX coil for different conditions, using the same amount of coil as a conventional single-loop TX coil. The results show that by adjusting the TX coil to three different modes as the airgap varies from 50 mm to 250 mm, consistent output power is achieved with smaller variations in the input current and voltage compared to those in a conventional system. A conventional system requires an input voltage increase of approximately 529.64%, while the proposed system requires only a 42.93% increase. The proposed system enhances the power transfer capacity of the WPT system, particularly when operating in an over-coupling state. This approach provides a stable output power supply with a standardized and simplified TX coil structure.

Fabrication and characterization of model wireless biosensor-based electrochemical impedance spectroscopy (EIS) for detecting HER2 in plasma as therapeutics

PurposeEarly prediction of any type of cancer is important for the treatment of this type of disease, therefore, our target to evaluate whether monitoring early changes in plasma human epidermal growth factor receptor 2 (HER2) levels (using EIS), could help in the treatment of breast cancer or not? Human epidermal growth factor receptor 2 (HER2) overexpression is an important biomarker for treatment selection in earlier stages of cancers. The combined detection of the HER2 gene in plasma for blood cancer provides an important reference index for the prognosis of metastasis to other tissues. For this purpose, the authors fabricated and characterized a model wireless biosensor-based electrochemical impedance spectroscopy (EIS) for detecting HER2 plasma as therapeutics.Design/methodology/approachMost sensors generally are fabricated based on a connection between component of the sensors and the external circuits through wires. Although these types of sensors provide suitable sensitivities and also quick responses, the connection wires can be limited to the sensing ability in various devices approximately. Therefore, the authors designed a wireless sensor, which can provide the advantages of in vivo sensing and also long-distance sensing, quickly.FindingsThe biosensor structure was designed for detection of HER2, HER3 and HER-4 from lab-on-chip approach with six units of screen-printed electrode (SPE), which is built of an electrochemical device of gold/silver, silver/silver or carbon electrodes. The results exhibited that the biosensor is completely selective at low concentrations of the plasma and HER2 detection via the standard addition approach has a linearity plot, therefore, by using this type of biosensors HER2 in plasma can be detected.Originality/valueThis is then followed by detecting HER2 in real plasma using standard way which proved to have great linearity (R2 = 0.991) proving that this technique can be used to detect HER2 solution in real patients.

불완전 접촉으로 인한 아산화동 증식 발열 형상의 X-선 회절 분석 및 판별법에 대한 연구

불완전 접촉으로 인한 아산화동 증식 발열 형상의 X-선 회절 분석 및 판별법에 대한 연구

Real-time biological early-warning system based on freshwater mussels’ valvometry data

Abstract. Quantifying the effects of external climatic and anthropogenic stressors on aquatic ecosystems is an important task for scientific purposes and management progress in the field of water resources. In this study, we propose an innovative use of biotic communities as real-time indicators, which offers a promising solution to directly quantify the impact of these external stressors on the aquatic ecosystem health. Specifically, we investigated the influence of natural river floods on riverine biotic communities using freshwater mussels (FMs) as reliable biosensors. Using the valvometry technique, we monitored the valve gaping of FMs and analysed both the amplitude and frequency. The valve movement of the FMs was tracked by installing a magnet on one valve and a Hall effect sensor on the other valve. The magnetic field between the magnet and the sensor was recorded using an Arduino board, and its changes over time were normalised to give the opening percentage of the FMs (how open the mussels were). The recorded data were then analysed using continuous wavelet transform (CWT) analysis to study the time-dependent frequency of the signals. The experiments were carried out both in a laboratory flume and in the Paglia River (Italy). The laboratory experiments were conducted with FMs in two configurations: freely moving on the bed and immobilised on vertical rods. Testing of the immobilised configuration was necessary because the same configuration was used in the field in order to prevent FMs from packing against the downstream wall of the protection cage during floods or from breaking their connection wires. These experiments allowed us to verify that immobilised mussels show similar responses to abrupt changes in flow conditions as free mussels. Moreover, immobilised mussels produced more neat and interpretable signals than free-moving mussels due to the reduced number of features resulting from movement constraints. We then analysed the response of 13 immobilised mussels under real river conditions during a flood on 31 March 2022. The FMs in the field showed a rapid and significant change in valve gap frequency as the flood escalated, confirming the general behaviour observed in the laboratory in the presence of an abrupt increase in the flow. These results highlight the effectiveness of using FMs as biosensors for the timely detection of environmental stressors related to natural floods and emphasise the utility of CWT as a powerful signal-processing tool for the analysis of valvometry data. The study proposes the integration of FM valvometry and CWT for the development of operational real-time biological early-warning systems (BEWSs) with the aim of monitoring and protecting aquatic ecosystems. Future research should focus on extending the investigation of the responsiveness of FMs to specific stressors (e.g. turbidity, temperature, and chemicals) and on testing the applications of the proposed BEWSs to quantify the impact of both natural stressors (e.g. heat waves and droughts) and anthropogenic stressors (e.g. hydropeaking, reservoir flushing, and chemical contamination).

Improvement of Power Factor in Wireless Electric Vehicle Charging Using Inductive Power Transfer Topology

The EV requires energy supplied to its motors to function properly. This required energy either can be transmitted by a physical wired connection or by wireless power transfer firstly to the battery using charging of the EV system and then battery discharges to supply to the vehicle. This paper deals with the wireless transfer of power using the induction method for charging battery of the vehicle using electric energy for its functioning as it is the most suitable and fast mode to charge the batteries of many vehicles altogether at charging station. The challenges recently faced by EV’s includes the movement of energy from the energy supply point to the destination i.e., EV’s without the direct interaction of battery and energy source. Many topologies have been introduced in this regard and several simulation models are built.

ВЛИЯНИЕ ПРИМЕСЕЙ НА ДЕГРАДАЦИЮ СОЕДИНЕНИЙ В СИСТЕМЕ Al – Au

Typical reasons for degradation of micro–welded bimetallic compounds of the aluminum-gold binary system are considered. These types of compounds are often used in the manufacture of semiconductor products (SCPs) and integrated circuits (ICs). Degradation of compounds, revealed during screen tests or during products operating, leads to failures, which dramatically reduces the reliability of electronic equipment (EE). The majority of degradation processes are based on diffusion phenomena, which are mainly determined by temperature, chemical composition and microstructure of metals and alloys. Impurity elements included in the gold coating have a significant effect on the degradation of the wire connections such as crystal contact pads – traverses of package terminals of SCPs. In this regard, it is worth analyzing the effect of various impurities on the diffusion processes and changes in the microstructure of the coating in order to find out the most dangerous chemical elements and determine their role in the degradation of compounds. The paper presents a review of references on the research subject. In the conclusion, the results of analysis in the field of the influence of impurity elements on the degradation of compounds in Al – Au system are summarized, conclusions are drawn about the key role of grain-boundary diffusion on the degradation of micro-welded bimetallic compounds.

UV Laser Copper Pad Surface Exposure for Laser Direct Structuring (LDS) of Interconnection

Microelectronics market demands strong miniaturization and high-quality packages solutions; therefore, companies and researchers start thinking about alternative methods to create more flexible and performing interconnections which are able to reduce package dimensions. Laser direct structuring (LDS) technology creates a conductive pattern on MID (Moulded Interconnected Device) with the combination of laser layout structuring and electroplating bath. LDS can be applied to leadframe based IC packages to realize interconnections in alternative to standard wires connection. Feasibility study on copper (Cu) pad covered by moulding compound is conducted varying laser parameters as power, frequency and scanning speed to obtain a 80μm diameter via on die. Die via is connected through a trace with a 200μm diameter via on lead to realize the interconnection path, filled with copper after plating process. UV 355nm wavelength laser is used to obtain a complete exposition of Cu surface without silicon damage. Visual inspection with optical microscope and SEM analysis method are performed to evaluate the integrity of metal pads and interconnection layout.

Remotely disturbing bioelectrical homeostasis by nanoparticle-enabled intracellular electrical stimulation for wireless cancer therapy

Bioelectrical homeostasis plays critical roles in biological processes, but disturbing it for cancer therapy remains challenging due to the difficulty in electrically controlling cancer cells. Here we show that cell-internalized electroactive nanoparticles interrupt it in cancer cells to effectively treat cancer wirelessly. Specifically, K0.5Na0.5NbO3 ferroelectric nanoparticles are polarized and then generate a voltage of approximately −60 mV in response to ultrasound. Hence, once endocytosed by cancer cells in tumors, these nanoparticles establish an intracellular electric field (iEF) under the remote activation by ultrasound irradiation (for only 3 min) from outside the body. The iEF then depolarizes cell membrane potentials, decreases mitochondrial membrane potentials, and overloads intracellular calcium ions, disturbing intracellular bioelectrical balance. This disturbance promotes cancer cell apoptosis, inhibiting the growth of different types of tumors (bone tumor and skin tumor) without adverse effects. It is noteworthy that iEF can specifically disrupt the bioelectric balance of tumor cells but has no effect on normal cells. Such wireless cancer therapy can be achieved by other ferroelectric nanoparticles (e.g., BaTiO3). This work represents the first cancer treatment paradigm by intracellularly interrupting bioelectrical homeostasis remotely to cause cancer cell dysfunctions without electrode implantation and wire connection in vivo. It can also provide biologists with new tools for studying the role of disturbed bioelectrical homeostasis in cell fates and disease progression.

Research on uninterruptable power supply technology for auxiliary winding of electric locomotive while passing the neutral section

PurposeAuxiliary power system is an indispensable part of the train; the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways, which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters. Powered by DC-link voltage of traction converters, the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking. Meanwhile, powered by traction transformers, the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approachUninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied. Failure reasons why previous solutions cannot be realized are analyzed. An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper. The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive. This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.FindingsThis scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid. Control objectives of uninterrupted power supply technology are proposed, which are no overvoltage, no overcurrent and uninterrupted power supply.Originality/valueThe control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section. Furthermore, this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.

Research on the applications of the wireless communication

Wireless communication transmits information, data, and signals across a spatial expanse without physical wired connections. The transmission of information is facilitated through the utilization of electromagnetic waves, which propagate through several mediums, including the air. The paper mainly examines the development process, the significant impact of wireless communication on individuals, the fundamental operating principles of wireless communication, and wide-used techniques and their applications in wireless communication. However, we also acknowledge the shortcomings and constraints of the existing wireless communication systems, and we are confronted with the challenge of identifying a viable approach to implement an improved and more comprehensive version of it. Luckily, it is anticipated that the future of wireless communication will yield promising prospects and contribute to notable progress in diverse fields. In conclusion, it is evident that despite the existing challenges in current wireless communication techniques, there is optimism for a promising future. This is attributed to the anticipated emergence of expanded applications and further enhancements facilitated by the continuous advancement and refinement of wireless communication techniques.

Remotely Controlled Laser‐Programmable Microwave Metasurfaces

AbstractProgrammable metasurfaces have brought significant advance to electromagnetic (EM) and related fields, making it easier and more efficient to manipulate the EM waves and realize higher tuning flexibility and range. However, how to achieve independent control of each unit of the programmable metasurface in a low‐overhead and wireless manner remains a challenge. Here, a laser‐programmable microwave metasurface is proposed and constructed, in which each unit can be controlled remotely by laser intensity in real time. The key is to design an ultra‐compact photoelectric passive boost circuit and integrate it into the meta‐unit. In this case, the light sensing‐to‐power‐to‐control‐to‐microwave manipulation process can be fully realized on the highly integrated meta‐unit, and thus the metasurface can be completely programmed at the unit level by laser coding patterns, without any wire connections and external power suppliers. As experimental demonstration, a phase‐coding laser‐programmable microwave metasurface is presented using a laser array. To show the capabilities of the metasurface, 2D beam scanning and vortex beam generation are demonstrated using 1‐bit phase modulations under the laser illuminations. This approach offers an effective route for the space lasers to manipulate microwaves accurately, which is helpful in developing advanced functional devices, passive platforms, and photoelectric hybrid systems.

Printed smart devices for anti-counterfeiting allowing precise identification with household equipment

Counterfeiting has become a serious global problem, causing worldwide losses and disrupting the normal order of society. Physical unclonable functions are promising hardware-based cryptographic primitives, especially those generated by chemical processes showing a massive challenge-response pair space. However, current chemical-based physical unclonable function devices typically require complex fabrication processes or sophisticated characterization methods with only binary (bit) keys, limiting their practical applications and security properties. Here, we report a flexible laser printing method to synthesize unclonable electronics with high randomness, uniqueness, and repeatability. Hexadecimal resistive keys and binary optical keys can be obtained by the challenge with an ohmmeter and an optical microscope. These readout methods not only make the identification process available to general end users without professional expertise, but also guarantee device complexity and data capacity. An adopted open-source deep learning model guarantees precise identification with high reliability. The electrodes and connection wires are directly printed during laser writing, which allows electronics with different structures to be realized through free design. Meanwhile, the electronics exhibit excellent mechanical and thermal stability. The high physical unclonable function performance and the widely accessible readout methods, together with the flexibility and stability, make this synthesis strategy extremely attractive for practical applications.

Wireless internet of things solutions for efficient photovoltaic system monitoring via WiFi networks

<div align="center"><span>The imperative for sustainable energy production has necessitated the significant expansion of renewable energy sources, particularly photovoltaic (PV) systems. The utilization of real-time monitoring and data analysis is imperative to enhance the efficiency and performance of photovoltaic systems. This abstract presents developing and deploying a wireless monitoring system for a photovoltaic system. The system utilizes a Raspberry Pi device connected to a WiFi network and an SD card for data storage to enable remote monitoring and management of PV systems. The proposed monitoring system comprises a Raspberry Pi equipped with sensors to measure various parameters such as voltage, current, temperature, and the ambient conditions of the solar panels; the monitoring system can be remotely accessible through the wireless capabilities of the Raspberry Pi, which are activated by establishing a connection to an existing WiFi network. The proposed configuration facilitates the placement of the monitoring station in any desired location, hence eliminating the requirement for intricate wiring connections. These real-time data enable solar system managers to quickly identify anomalies, anticipate breakdowns, and optimise energy production. The paper presents a wireless monitoring system with a cost-effective and scalable solution for monitoring photovoltaic systems.</span></div>

Effectiveness of Modes of Radio Broadcasting in Gain and Retention of Knowledge About Child Care Message

Abstract: India is dominantly a country of villages. There is a great necessity for transmitting latest scientific knowledge about agriculture and related fields among the farming communities. Today we have many problems- high rate of illiteracy, accelerating population growth which eats into any gain that educational expansion may bring, increasing pressures on admissions at all stages, explosion in knowledge necessitating change and review of curricula and teaching method, urban – rural imbalance, wastage in education need for raising standards and the criterion of an environment favourable to social change and capable of softening its harsher incidences. The mass media are supremly adapted to adult education. Radio is the transmission and reception of signals by means of electric waves without the use of connection wires. Therefore, this study was undertaken with a view to find out relative effectiveness of three mode of presentation

Piezo-Acoustic Resistive Switching Behaviors in High-Performance Organic-Inorganic Hybrid Perovskite Memristors.

Memristors are regarded as promising candidates for breaking the problems including high off-chip memory access delays and the hash rate cost of frequent data moving induced by algorithms for data-intensive applications of existing computational systems. Recently, organic-inorganic halide perovskites (OIHPs) have been recognized as exceptionally favorable materials for memristors due to ease of preparation, excellent electrical conductivity, and structural flexibility. However, research on OIHP-based memristors focuses on modulating resistive switching (RS) performance through electric fields, resulting in difficulties in moving away from complex external circuits and wire connections. Here, a multilayer memristor has been constructed with eutectic gallium and indium (EGaIn)/ MAPbI3 /poly(3,4-ethylenedioxythiophene): poly(4-styrenesulphonate) (PEDOT: PSS)/indium tin oxide (ITO) structure, which exhibits reproducible and reliable bipolar RS with low SET/RESET voltages, stable endurance, ultrahigh average ON/OFF ratio, and excellent retention. Importantly, based on ion migration activated by sound-driven piezoelectric effects, the device exhibits a stable acoustic response with an average ON/OFF ratio greater than 103 , thus realizing non-contact, multi-signal, and far-field control in RS modulation. This study provides a single-structure multifunctional memristor as an integrated architecture for sensing, data storage, and computing.